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Synthesis of a malaria candidate glycosylphosphatidylinositol （GPI） structure： A strategy for fully inositol acylated and phosphorylated GPIs

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天然产物研究与开发 2004年第4期16卷 306-306页

作者： LuJ JayaprakashKn SchlueterU fraser-ReidB

A congener of the glycosylpbosphatidylinositol (GPI) membrane anchor present on the cell surface of the malaria pathogen Plasmodium, falciparum has been synthesized. This GPI is an example of a small number of such membrane anchors that carry a fatty acyl group at 0-2 of the inositol. Although the acyl group plays crucial roles in GPI biosynthesis, it rarely persits in mature *** notable examples are the mammalian GPIs CD52 and AchE. The presence of bulky functionalities at three contiguous positions of the inositol moiety creates a very crowded environment that poses difficulties for carrying out selective chemical *** installations of the axial long-chain acyl group and neighboring pbosphoglyceryl complex were fraught with obstacles. The key solution to these obstacles in the successful synthesis of the malarial candidate and prototype structures involved stereoelectronically controlled opening of a cyclic ortho ester. The reaction proceeds in very good yields, the desired axial diastereomer being formed predominantly, even more so in the case of long-chain acyl derivatives. The myoinositol precursor was prepared from methyl alpha-D-glu-copyranoside by the biornimetic procedure of Bender and Budhu. For the glycan array, advantage was taken of the fact that (a) n-pentenyl ortho ester donors are rapidly and chemospecifically activated upon treatment with ytterbium triflate and n-iedosueeinimide and (b) coupling to an aeeeptor affords alpha-coupled product exclusively. A strategy for obtaining the GPI's alpha-glucosaminide component from the corresponding a-mannoside employed Deshong's novel azide displacement procedure. Thus all units of the glycan array were obtained from a beta-D-manno-n-pentenyl ortho ester, this being readily prepared from D-mannose in three easy, high-yielding steps. The "crowded environment" at positions 1 and 2, noted above, could conceivably be relieved by migration of the acyl group to the neighboring cis-O-3-hydr

关键词：糖基磷脂酰环己六醇疟疾环己六醇磷酸化酰化生物合成寄生物

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1999年5月11日太阳风几乎消失时的极区电离层

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中国科学：数学 2001年第S1期39卷 137-141页

作者：胡红桥刘瑞源刘勇华杨惠根刘顺林张北辰艾勇 n. Sato B. J. fraser 中国极地研究所上海200129 武汉大学电子信息学院光电信息工程系武汉430072 national Institute of Polar Research Tokyo173 Japan Department of Physics University of Newcastle Australia

1999年5月11日太阳风几乎消失,其等离子体密度不到1 cm^(-3),动压不到0.1nPa,而行星际磁场持续北向.对这一特殊事件日和控制日(1999年5月14日)南极中山站极区电离层多手段观测结果进行了对比分析.结果表明中山站在1999年5月11日地磁活... 详细信息

1999年5月11日太阳风几乎消失,其等离子体密度不到1 cm^(-3),动压不到0.1nPa,而行星际磁场持续北向.对这一特殊事件日和控制日(1999年5月14日)南极中山站极区电离层多手段观测结果进行了对比分析.结果表明中山站在1999年5月11日地磁活动极为宁静,通常在地磁当地时的中午前后出现的地磁脉动在这一天几乎没有;电离层成层明显而稳定,F_2层扩展很小;日侧F_2层临界频率明显高于控制日,且f_oF_2的峰值早约2 h出现;电离层漂移速度有所减小;在地磁当地时的中午附近出现了很强的极光E层,这一切都说明极区电离层异常平静,地磁场的偶极化更为明显.但子夜前出现有类似极光亚暴的征兆,如地磁H分量明显的负扰。

关键词：太阳风南极中山站极区电离层地磁脉动

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Risk factors for fracture in adult kidney transplant recipients

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World Journal of Transplantation 2016年第2期6卷 370-379页

作者： Kyla L naylor Guangyong Zou William D Leslie Anthony B Hodsman ngan n Lam Eric McArthur Lisa-Ann fraser Gregory A Knoll Jonathan D Adachi S Joseph Kim Amit X Garg Institute for Clinical Evaluative Sciences 2nd Institute of Health Policy Management and EvaluationUniversity of Toronto Department of Epidemiology and Biostatistics Western University Department of Medicine University of Manitoba Division of nephrology Western University Division of nephrology University of Alberta Division of Endocrinology Western University Division of nephrology Kidney Research CentreOttawa Hospital Research InstituteUniversity of Ottawa Division of Rheumatology McMaster University Division of nephrology University Health NetworkUniversity of Toronto

AIM: To determine the general and transplant-specific risk factors for fractures in kidney transplant ***: We conducted a cohort study of all adults who received a kidney-only transplant(n = 2723) in Ontario, Canada between 2002 and 2009. We used multivariable Cox proportional hazards regression to determine general and transplant-specific risk factors for major fractures(proximal humerus, forearm, hip, and clinical vertebral). The final model was established using the backward elimination strategy, selecting risk factors with a P-value ≤ 0.2 and forcing recipient age and sex into the model. We also assessed risk factors for other fracture locations(excluding major fractures, and fractures involving the skull, hands or feet). RESULTS: There were 132 major fractures in the follow-up(8.1 fractures per 1000 person-years). General risk factors associated with a greater risk of major fracture were older recipient age [adjusted hazard ratio(a HR) per 5-year increase 1.11, 95%CI: 1.03-1.19] and female sex(a HR = 1.81, 95%CI: 1.28-2.57). Transplant-specific risk factors associated with a greater risk of fracture included older donor age(5-year increase)(a HR = 1.09, 95%CI: 1.02-1.17) and end-stage renal disease(ESRD) caused by diabetes(a HR = 1.72, 95%CI: 1.09-2.72) or cystic kidney disease(a HR = 1.73, 95%CI: 1.08-2.78)(compared to glomerulonephritis as the reference cause). Risk factors across the two fracture locations were not consistent(major fracture locations vs other). Specifically, general risk factors associated with an increased risk of other fractures were diabetes and a fall with hospitalization prior to transplantation, while length of time on dialysis, and renal vascular disease and other causes of ESRD were the transplant-specific risk factors associated with a greater risk of other ***: Both general and transplant-specific risk factors were associated with a higher risk of fractures in kidney transplant recipients. Results ca

关键词： Fracture Risk factors Kidney transplant recipient Prognostication Cohort study

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CO_2 adsorption using TiO_2 composite polymeric membranes:A kinetic study

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Journal of Environmental Sciences 2015年第9期27卷 163-171页

作者： Sarah Hafeez X.Fan Arshad Hussain C.F.Martín School of Chemical and Materials Engineering (SCME) National University of Sciences & Technology Institute for Materials and Processes School of Engineering University of Edinburgh University of Aberdeen School of Engineering Fraser Noble Building King's College

CO2is the main greenhouse gas which causes global climatic changes on larger scale. Many techniques have been utilised to capture CO2. Membrane gas separation is a fast growing CO2 capture technique, particularly gas separation by composite membranes. The separation of CO2 by a membrane is not just a process to physically sieve out of CO2 through the controlled membrane pore size. It mainly depends upon diffusion and solubility of gases, particularly for composite dense membranes. The blended components in composite membranes have a high capability to adsorb CO2. The adsorption kinetics of the gases may directly affect diffusion and solubility. In this study, we have investigated the adsorption behaviour of CO2 in pure and composite membranes to explore the complete understanding of diffusion and solubility of CO2 through membranes. Pure cellulose acetate（CA） and cellulose acetatetitania nanoparticle（CA-TiO2） composite membranes were fabricated and characterised using SEM and FTIR analysis. The results indicated that the blended CA-TiO2 membrane adsorbed more quantity of CO2 gas as compared to pure CA membrane. The high CO2 adsorption capacity may enhance the diffusion and solubility of CO2 in the CA-TiO2 composite membrane, which results in a better CO2 separation. The experimental data was modelled by Pseudo first-order, pseudo second order and intra particle diffusion *** to correlation factor R2, the Pseudo second order model was fitted well with experimental data. The intra particle diffusion model revealed that adsorption in dense membranes was not solely consisting of intra particle diffusion.

关键词： Global warming Cellulose acetate Gas adsorption Pseudo order models CO2 Ti O2

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Effect of electric boundary conditions on crack propagation in ferroelectric ceramics

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Acta Mechanica Sinica 2014年第2期30卷 153-160页

作者： F.-X. Li Y.Sun R.K.n.D.Rajapakse State Key Laboratory for Turbulence and Complex Systems College of EngineeringPeking University Faculty of Applied Sciences Simon Fraser University

In this paper, the effect of electric boundary conditions on Mode I crack propagation in ferroelectric ceramics is studied by using both linear and nonlinear piezoelectric fracture mechanics. In linear analysis, impermeable cracks under open circuit and short circuit are analyzed using the Stroh formalism and a rescaling method. It is shown that the energy release rate in short circuit is larger than that in open circuit. In nonlinear analysis, permeable crack conditions are used and the nonlinear effect of domain switching near a crack tip is considered using an energy-based switching criterion proposed by Hwang et al.（Acta Metal. Mater.,1995）. In open circuit, a large depolarization field induced by domain switching makes switching much more diffcult than that in short circuit. Analysis shows that the energy release rate in short circuit is still larger than that in open circuit, and is also larger than the linear result. Consequently,whether using linear or nonlinear fracture analysis, a crack is found easier to propagate in short circuit than in open circuit, which is consistent with the experimental observations of Kounga njiwa et al.（Eng. Fract. Mech., 2006）.

关键词： Ferroelectric ceramics Crack propagation En-ergy release rate Electric boundary conditions Domain switching

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病危患者的胃窦-幽门—十二指肠运动对胃和十二指肠营养素的反应

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世界核心医学期刊文摘（胃肠病学分册） 2006年第4期2卷 32-33页

作者： Chapman M fraser R Vozzo R. 纪泛扑 Intensive Care Unit Royal Adelaide Hospital North Terrace Adelaide SA 5000 Australia

Background: Gastric emptying is frequently delayed in critical illness which compromises the success of nasogastric nutrition. The underlying motor dysfunctions are poorly defined. Aims: To characterise antro-pyloro-duodenal motility during fasting, and in response to gastric and duodenal nutrient, as well as to ev aluate the relationship between gastric emptying andmotility, in the critically ill. Subjects: Fifteen mechanically ventilated patients from a mixed intensive c are unit; 10 healthy volunteers. Methods: Antro-pyloro-duodenal pressures were recorded during fasting, after intragastric administration (100 ml; 100 kcal), and during small intestinal infusion of liquid nutrient (6 hours; l kcal/min). G astric emptying was measured using a 13C octanoate breath test. Results: In heal thy subjects, neither gastric nor small intestinal nutrient affected antro-pylo ro-duodenal pressures. In patients, duodenal nutrient infusion reduced antral a ctivity compared with both fasting and healthy subjects (0.03 (0-2.47) waves/mi n v 0.14 (0-2.2) fasting (p = 0.016); and v 0.33 (0-2.57)/min in healthy subje cts (p = 0.005)). Basal pyloric pressure and the frequency of phasic pyloric pre ssure waves were increased in patients during duodenal nutrient infusion (3.12 ( 1.06) mm Hg; 0.98 (0.13)/min) compared with healthy subjects (-0.44 (1.25) mm H g; p nutes; 0.29 (0.15)/min; p = 0.0002) and with fasting (- 0.06 (1.05) mm Hg; p nutes; 0.49 (0.13)/min; (p = 0.0001). Ga stric emptying was delayed in patients (gastric emptying coefficient 2.99 (0.2) v 3.47 (0.1); p = 0.015) and inversely related to the number of pyloric pressure waves (r = -0.563, p = 0.029). Conclusions: Stimulation of pyloric and suppres sion of antral pressures by duodenal nutrient are enhanced in the critically ill and related to decreased gastric emptying.

关键词：呼气试验健康受试者鼻胃管胃排空延迟胃排空功能蠕动波重症监护输注液体辛酸盐功能障碍

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Morphine has latent deleterious effects on the ventilatory responses to a hypoxic challenge

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Open Journal of Molecular and Integrative Physiology 2013年第3期3卷 166-180页

作者： Walter J. May Ryan B. Gruber Joseph F. Discala Veljko Puskovic fraser Henderson Jr. Lisa A. Palmer Stephen J. Lewis Pediatric Respiratory Medicine University of Virginia School of Medicine Charlottesville USA Division of Biology Galleon Pharmaceuticals Horsham USA

The aim of this study was to determine whether morphine depresses the ventilatory responses elicited by a hypoxic challenge (10% O2, 90% n2) in conscious rats at a time when the effects of morphine on arterial blood gas (ABG) chemistry, Alveolar-arterial (A-a) gradient and minute ventilation (Vm) had completely subsided. In vehicle-treated rats, each episode of hypoxia stimulated ventilatory function and the responses generally subsided during each normoxic period. Morphine (5 mg/kg, i.v.) induced an array of depressant effects on ABG chemistry, A-a gradient and Vm (via decreases in tidal volume). Despite resolution of these morphine-induced effects, the first episode of hypoxia elicited substantially smaller increases in Vm than in vehicle-treated rats, due mainly to smaller increases in frequency of breathing. The pattern of ventilatory responses during subsequent episodes of hypoxia and normoxia changed substantially in morphine-treated rats. It is evident that morphine haslatent deleterious effects on ventilatory responses elicited by hypoxic challenge.

关键词： Morphine Hypoxia Minute Ventilation Arterial Blood Gas Chemistry Conscious Rats

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THE IAM TSAU CLInIC FOR PATIEnTS SUFFERInG FROM LEPROSY

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Chinese Medical Journal 1936年第5期50卷

作者： n.D.fraser M.B. CH.B. D.T.M. D.T.H.

A report is made on the organisation and work of a village clinicfor the treatment of patients suffering from *** six months 128 cases had been registered at the clinic.29 cases are presumed to have discontinued *** remain-ing 99 are attending on the whole with satisfactory *** large proportion of neural cases(50 per cent)is noted. A brief note is made of the progress of the cases under *** cost of the clinic works out at 25 cents per visit (whichincludes ＄106,the cost of building a shelter for the clinic.)

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Is tax evasion macho?Testosterone,personality traits and evasion

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Economic and Political Studies 2023年第3期11卷 295-315页

作者： Marcelo Arbex Justin M.Carre Shawn n.Geniole Enlinson Mattos Department of Economics University of WindsorOntarioCanada Programa de Pos-Graduacao em Economia Universidade Federal do CearaFortalezaBrazil Psychology Department Nipissing UniversityNipissingCanada Department of Psychology University of the Fraser ValleyAbbotsfordCanada neuropsychopharmacology and Biopsychology Unit University of ViennaViennaAustria Social neuroendocrinology Lab Nipissing UniversityNipissingCanada Sao Paulo School of Economics Fundacao Getulio VargasSao PauloBrazil

This paper examines the potential effects of testosterone and personality traits on the decision to evade *** a series of experiments,subjects completed behavioural tasks and made a one-shot tax evasion *** estimate a negative weakly significant treatment effect,which suggests that an exogenous increase in the testosterone level may inhibit the decision to evade *** results also suggest that higher dominance and independent self-construal,as well as lower self-control,are associated with a greater likelihood of tax *** discuss the mechanisms potentially linking testosterone to tax *** findings support the inclusion of biological factors in the analysis of tax evasion behaviour.

关键词： Tax compliance testosterone personality traits experiment

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Size dependency and potential field influence on deriving mechanical properties of carbon nanotubes using molecular dynamics

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Theoretical & Applied Mechanics Letters 2015年第4期5卷 167-172页

作者： K.G.S.Dilrukshi M.A.n.Dewapriya U.G.A.Puswewala Department of Civil Engineering University of Moratuwa School of Engineering Science Simon Fraser University

A thorough understanding on the mechanical properties of carbon nanotube （CnT） is essential in extending the advanced applications of CnT based systems. However, conducting experiments to estimate mechanical properties at this scale is extremely challenging. Therefore, development of mechanistic models to estimate the mechanical properties of CnTs along with the integration of existing continuum mechanics concepts is critically important. This paper presents a comprehensive molecular dynamics simulation study on the size dependency and potential function influence of mechanical properties of CnT. Commonly used reactive bond order （REBO） and adaptive intermolecular reactive bond order （A1REBO） potential functions were considered in this regard. Young＇s modulus and shear modulus of CnTs are derived by integrating classical continuum mechanics concepts with molecular dynamics simulations. The results indicate that the potential function has a significant influence on the estimated mechanical properties of CnTs, and the influence of potential field is much higher when studying the torsional behaviour of CnTs than the tensile behaviour.

关键词： Carbon nanotubes Molecular dynamics Potential field Shear modulus Poisson's ratio

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